Disclaimer

Estimates only

Every weight, size and comparison on Gem Carat Calculator is an estimate calculated from measurements and published formulas. Estimates can differ from a stone's true weight or size, sometimes by more than the range shown, for reasons the formulas cannot see. Only a calibrated scale gives true weight, and only a qualified professional can identify or grade a stone.

Not an appraisal or valuation

Nothing on this site is an appraisal, a grading report, a valuation or an offer. The price per carat calculator performs arithmetic on numbers you provide and says nothing about what any stone is worth.

No professional advice

The content is general information for educational purposes. It is not professional gemological, legal, financial or insurance advice. Do not rely on it for purchases, sales, insurance or disputes without independent confirmation.

No affiliation

We cite the International Gem Society, the GIA, the USGS and trade references as sources. We are not affiliated with or endorsed by any of them, or by any laboratory, retailer or supplier. Trade names belong to their owners.

Accuracy

We work hard to keep data accurate and record where sources disagree, but we cannot guarantee that every value is error-free. If you spot a problem, please tell us.

Limitation of liability

To the extent permitted by law, we are not liable for any loss arising from use of the site or reliance on its results. See the terms of use.